1. Field of the Invention
The present invention relates to microcircuit fabrication. More specifically, the present invention relates to a method and an apparatus to facilitate fabrication of electromagnetic, optical, chemical, and mechanical systems using chemical endpoint detection.
2. Related Art
The dramatic advances in computer system performance during the past 20 years can largely be attributed to improvements in the processes that are used to fabricate integrated circuits. By making use of the latest fabrication processes, integrated circuit designers can presently integrate computing systems comprised of hundreds of millions of transistors onto a single semiconductor die which is a fraction of the size of a human fingernail.
Recent advances in construction techniques allow types of circuit elements other than transistors to be fabricated on semiconductor wafers. These other types of circuit elements include, but are not limited to, optical components, fiber optic channels, fluid channels, piezoelectric devices, peltier devices, electromechanical components, quantum effect devices, and combinations of these components. These circuit elements can also be combined into three-dimensional structures.
A typical fabrication process builds structures through successive cycles of layer deposition and subtractive processing, such as etching. As the dimensions of individual circuit elements continue to decrease, it is becoming necessary to more tightly control the etching operation. For example, in a typical etching process, etching is performed for an amount of time that is estimated by taking into account the time to etch through a layer to reach an underlying layer, and the time to over-etch into the underlying layer. However, this process can only be controlled to +/xe2x88x92100 Angstroms, which can be a problem when fine control of dimensions is required.
Additionally, these smaller dimensions create alignment problems when coupling these devices together or when attaching external components such as wires and optical fibers. Systems that bring together multiple semiconductor die require accurate alignment to allow coupling of optical signals, electrical signals, mechanical devices, and fluid pipes from one semiconductor die to another semiconductor die.
What is needed is a method and an apparatus to facilitate fabrication of electromagnetic, optical, chemical, and mechanical systems and interconnection structures that do not display the problems described above.
One embodiment of the present invention provides a system that facilitates construction of electromagnetic, optical, chemical, and mechanical systems using chemical endpoint detection. The system operates by receiving a system description that specifies multiple components, including a first component and a second component. The system fabricates the first component and the second component using selected construction materials. The system also creates a first interconnection structure on the first component and a second interconnection structure on the second component. These interconnection structures can be created using a sacrificial layer and chemical endpoint detection. Next, the system brings the first component and the second component together by connecting the first interconnection structure and the second interconnection structure. These interconnection structures align the first component to the second component so that accurate alignment can be achieved.
In one embodiment of the present invention, the selected construction material includes Si, SiGe, or SiGeC.
In one embodiment of the present invention, chemical endpoint detection involves selectively etching the selected construction material.
In one embodiment of the present invention, tetramethylammonium hydroxide (TMAH) or potassium hydroxide (KOH-H2O) is used to selectively etch Si.
In one embodiment of the present invention, hydrofluoric/nitric/acetic (HNA) acids are used to selectively etch SiGe, and SiGeC.
In one embodiment of the present invention, the first component includes one of an electromagnetic component, an optical component, a chemical component, a mechanical component, or other components.
In one embodiment of the present invention, the second component includes one of an electromagnetic component, an optical component, a chemical component, a mechanical component, or other components.
In one embodiment of the present invention, the system fabricates locking structures on the first interconnection structure and the second interconnection structure, so that the first component and the second component are locked together when the first interconnection structure is connected to the second interconnection structure.
In one embodiment of the present invention, the system fabricates gaskets on the first interconnection structure and the second interconnection structure, so that the interface between the first component and the second component are sealed to prevent leakage when the first interconnection structure is inserted into the second interconnection structure.
In one embodiment of the present invention, the system creates a third interconnection structure, wherein the third interconnection structure can accept either an individual optical fiber, an individual wire, a fluidic channel, or other connectors.
In one embodiment of the present invention, the first component and the second component are constructed on a single substrate.
In one embodiment of the present invention, the first component is constructed on a first substrate and the second component is constructed on a second substrate.